Atlantic herring (Clupea harengus) are an important prey species for a range of predators in the Gulf of Maine including marine mammals, seabirds and groundfish (e.g., cod).
Herring also support a ~$420M (2011) lobster fishery; more than 70% of landed herring is used as lobster bait (Saila 2002).
Annual catch limit (ACL) for herring, determined from stock assessments, is divided among 4 spatial management areas (Figure 1 below) according to estimates of relative biomass among areas (Correia 2012); there is considerable uncertainty in these estimates due to difficulties in assessing the spatial distribution of the herring stock complex (particularly inshore).
Despite this, herring quotas have been reduced in the last 7 years, most notably in Area 1A where ACL has declined by almost 50% since 2006 (Figure 2 below).
Given uncertainties in how to allocate ACL among areas and that Area 1A is an important source of bait for the Maine lobster industry, a collaborative inshore herring acoustic survey was undertaken starting in 2012 using MTI funded equipment installed on lobster vessels to better inform ACL allocations for the benefit of the Maine lobster industry and the sustainability of the herring resource.
Figure 1: Management areas for Atlantic herring in U.S. waters. Spawning closure areas are part of Area 1A. The dashed contour line is at 90 m bathymetric depth. Shaded region indicates general survey area of the NMFS offshore herring acoustic survey (discontinued).
Figure 2: Trends in ACL (annual catch limit) for different sub-areas that make up the northeast herring complex. Note the major decline in Area 1A allocation (48% reduction since 2006). It is unknown whether the proportional distribution of ACL is appropriate.